1. Field of the Invention
The invention relates generally to network processing in an operating system (hereinafter referred to as “OS”) and is a technique applicable to server applications such as a WEB server and file server, and to consolidation of NAS (Network Attached Storage).
2. Description of Related Art
In order to consolidate the operation management of a server machine and to reduce management costs, consolidation is suggested, in which the same kinds of services provided by each server application in a plurality of server machines are consolidated in a single server machine. The service indicates, for example, a WEB service or NFS service, and enables to utilize software features via a network.
Usually, a server application in each server machine uses a particular address called an ANY address as an address for expecting a request issued by a client. The ANY address is a technique capable of expecting all requests sent to IP addresses held in the server machine (for example, see W. Richard Stevens, UNIX Network Programming, p.p. 278-289 Prentice Hall PTR, 1990).
When each server machine consolidates server applications (hereinafter referred to as “same server applications”) providing the same kinds of services, a plurality of the same server applications cannot be simply run on a single server machine.
If a plurality of the same server applications simply runs on a single server machine, it means that the server machine has a plurality of server applications with ANY addresses for expecting requests, and the server machine cannot determine which server application the requests should be received at.
For example, the following method for consolidation is suggested. First, a method using virtual machine software is suggested. The virtual machine software is capable of providing a plurality of virtual machines on a single server machine. An independent OS can run in each virtual machine. Consolidation can be achieved by providing one virtual machine for each consolidation source sever machine, and running the same kinds of server application on each virtual machine (see: (a)    http://www.vmware.com/pdf/virtualization.pdf; (b)    http://www.vmware.com/files/pdf/VMware_paravirtualization.pdf; and (c)    http://www.vmware.com/pdf/virtualization_considerations.pdf).
In another method, consolidation is achieved in a single server application on a single server machine by integrating configuration information on the service provided in a plurality of server machines. For example, when each server machine individually manages user information on services, user information is integrated beforehand.